notesnook-sync-server_customPrivateV1/Streetwriters.Common/Extensions/WampRealmExtensions.cs

/*
This file is part of the Notesnook Sync Server project (https://notesnook.com/)

Copyright (C) 2023 Streetwriters (Private) Limited

This program is free software: you can redistribute it and/or modify
it under the terms of the Affero GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Affero GNU General Public License for more details.

You should have received a copy of the Affero GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

using System;
using System.Reactive.Disposables;
using System.Threading;
using Microsoft.AspNetCore.Builder;
using Streetwriters.Common.Interfaces;
using WampSharp.AspNetCore.WebSockets.Server;
using WampSharp.Binding;
using WampSharp.V2;
using WampSharp.V2.Realm;

namespace Streetwriters.Common.Extensions
{
    public static class WampRealmExtensions
    {
        public static IDisposable Subscribe<T>(this IWampHostedRealm realm, string topicName, Action<T> onNext)
        {
            return realm.Services.GetSubject<T>(topicName).Subscribe<T>(onNext);
        }

        public static IDisposable Subscribe<T>(this IWampHostedRealm realm, string topicName, IMessageHandler<T> handler)
        {
            return realm.Services.GetSubject<T>(topicName).Subscribe<T>(async (message) => await handler.Process(message));
        }

        public static IDisposable SubscribeWithSemaphore<T>(this IWampHostedRealm realm, string topicName, IMessageHandler<T> handler)
        {
            var semaphore = new SemaphoreSlim(1, 1);
            var subscriber = realm.Services.GetSubject<T>(topicName).Subscribe<T>(async (message) =>
            {
                await semaphore.WaitAsync();
                try
                {
                    await handler.Process(message);
                }
                finally
                {
                    semaphore.Release();
                }
            });
            return Disposable.Create(() =>
            {
                subscriber.Dispose();
                semaphore.Dispose();
            });
        }
    }
}